Outlet-strut fracture and disc embolization in 27-mm and smaller Björk-Shiley convexo-concave valves: historical overview and 3 case reports.

Outlet-strut fracture leading to primary failure of Björk-Shiley convexo-concave disc valves has only recently been reported in valves of 27-mm size and smaller. We now report an additional 3 cases of outlet strut failure in smaller convexo-concave valves, in a series of 899 implantations (overall incidence, 0.33%) of convexo-concave valves in various sizes and in 2 variant opening angles (60 degrees and 70 degrees ), during a 6-year period. All failures were confined to lots implanted during 1981 and 1982. We describe these 3 cases within the context of an historical overview of the Björk-Shiley tilting-disc valve, and propose methods of surgical intervention when this life-threatening complication arises.